Various devices have been developed to observe, monitor, and/or record biotelemetry data for use in diagnosis and treatment of an individual. For example, electrocardiograms (EKGs) have been developed to monitor the electrical activity associated with a beating heart. By attaching electrical transducers to an individual at particular locations, an EKG may be utilized to provide graphical traces of heart activity. These graphical traces may include specific relevant portions, such as a P wave, QRS complex, T wave, U wave, P-R segment, S-T segment, PR interval, and QT interval, each useful in providing particular diagnostic information.
However, such EKGs have typically been very expensive and complex devices. For example, in order to provide all the information described above, EKGs have typically employed 12 leads, where leads are various combinations of signal paths associated with transducer electrodes placed upon the body.
Three of these leads, usually designated as leads I, II and III, are bipolar (i.e., they detect a change in electric potential between two points) and detect an electrical potential change in the frontal plane. Specifically, lead I is between a right arm electrode and a left arm electrode, the left arm electrode being positive. Lead II is between the right arm electrode and a left leg electrode, the left leg electrode being positive. Lead III is between the left arm electrode and the left leg electrode, the left leg electrode again being positive. The same three electrodes providing leads I, II and III discussed above are also typically used to form three unipolar leads, known as the augmented leads. These three augmented leads are referred to as aVR (right arm), aVL (left arm) and aVF (left leg), and also record a change in electric potential in the frontal plane. These augmented leads are unipolar in that they measure the electric potential at one point with respect to a null point (one which does not register any significant variation in electric potential during contraction of the heart). This null point is typically obtained for each lead by adding the potential from the other two leads. Additionally, six unipolar leads, each in a different position on the chest and monitoring electrical variations that occur directly under the electrode, record the electric potential changes in the heart in a cross sectional plane.
Properly placing this number of leads is often difficult, requiring the assistance of a trained professional. Additionally, equipment for monitoring all 12 leads and providing output of information with respect thereto typically must be complex. Moreover, the information provided by such prior art 12 lead EKGs typically requires reading by a trained professional in order to provide useful diagnostic information.
In addition to the complexity generally associated with the use of 12 leads, typical EKGs have additional functionality associated therewith, such as may be useful to professionals utilizing the EKG. For example, EKGs typically are adapted to monitor additional biotelemetry attributes, such as oxygen saturation. EKGs also generally include added functionality, such as including a cardiac defibrillator, a graph printer, and the like.
As can be readily appreciated from the above, prior art EKGs are typically provided in a relatively large, complex, and expensive form factor. Although not objectionable in a typical health care provider setting, such as a clinic or hospital, such EKGs are typically not widely available due to such size, complexity, and/or expense related considerations. For example, because of their size and expense, cardiac patients typically do not have availability of EKG machines in their home or office for monitoring and diagnostic purposes. Accordingly, a cardiac patient, or any individual who suspects a heart related anomaly, must typically present himself at a hospital emergency room, or other health care provider facility, in order to have access to an EKG machine for monitoring and diagnosis. Moreover, even if a typical prior art EKG machine were available to such a patient, such as in the patient's home or office, the use of such a device by the patient would be of limited usefulness as the information presented by the EKG would still require interpretation by a trained professional.
Accordingly, a vast amount of time and money are needlessly wasted each year in association with the limited availability of such biotelemetric machines. For example, patients with cardiac type symptoms, such as tightness in the chest, shortness of breath, light headedness, etcetera, must wait in a crowded hospital emergency room or clinic to be placed upon an EKG machine for monitoring and pay the services of a physician and for the use of the EKG machine only to discover that a benign condition, such as a gastrointestinal anomaly, was the cause.
Some attempts have been made to address problems associated with such limited availability of such biotelemetric machines, resulting in such devices as the Holter monitor and various forms of event recorders. However, these devices are themselves not without disadvantages.
The Holter monitor, for example, was initially developed as a 75 pound backpack to be worn by a patient to record the EKG of the wearer and transmit the signal to a host system. Since its introduction, the device has been greatly reduced in size, providing a more portable form factor, allowing for more freedom of movement with respect to its wearer. However, the use of a typical Holter monitor does not provide its wearer with information, but rather digitally records the EKG information for downloading and analysis by a trained professional at a later time.
Similarly, typical event recorders available today do not provide information to a user, but rather simply record an event for later analysis by a trained professional. For example, EKG recording by an event recorder may be initiated as the patient experiences particular symptoms in order to record the EKG coincident with the symptoms. This recorded information may be downloaded for analysis by a trained professional, possibly with notes by the patient as to the particular symptoms experienced at that time, at a later time.
Accordingly, a need exists in the art for acquisition, presentation, and/or analysis of biotelemetry data in real-time to a patient. A further need exists in the art for machines providing such biotelemetry data to be portable and relatively inexpensive to facilitate their deployment and widespread use by ambulatory patients.